Unrestrict version of PolymerElements/iron-list and update it

third_party/polymer/v1_0/components-chromium/iron-list/README.md

Index: third_party/polymer/v1_0/components-chromium/iron-list/README.md
diff --git a/third_party/polymer/v1_0/components-chromium/iron-list/README.md b/third_party/polymer/v1_0/components-chromium/iron-list/README.md
index 1b31769aaed70e97bb70833242de261fbac1e0d6..45dba7081ec3a8f076af3ef43fe09b0d8fe86a9b 100644
--- a/third_party/polymer/v1_0/components-chromium/iron-list/README.md
+++ b/third_party/polymer/v1_0/components-chromium/iron-list/README.md
@@ -7,6 +7,9 @@ iron-list.html
 Edit those files, and our readme bot will duplicate them over here!
 Edit this file, and the bot will squash your changes :)
 
+The bot does some handling of markdown. Please file a bug if it does the wrong
+thing! https://github.com/PolymerLabs/tedium/issues
+
 -->
 
 [![Build Status](https://travis-ci.org/PolymerElements/iron-list.svg?branch=master)](https://travis-ci.org/PolymerElements/iron-list)
@@ -16,8 +19,6 @@ _[Demo and API Docs](https://elements.polymer-project.org/elements/iron-list)_
 
 ##<iron-list>
 
-
-
 `iron-list` displays a virtual, 'infinite' list. The template inside
 the iron-list element represents the DOM to create for each list item.
 The `items` property specifies an array of list item data.
@@ -39,12 +40,14 @@ layout means (e.g. the `flex` or `fit` classes).
 
 List item templates should bind to template models of the following structure:
 
-    {
-      index: 0,     // data index for this item
-      item: {       // user data corresponding to items[index]
-        /* user item data  */
-      }
-    }
+```js
+{
+  index: 0,        // index in the item array
+  selected: false, // true if the current item is selected
+  tabIndex: -1,    // a dynamically generated tabIndex for focus management
+  item: {}         // user data corresponding to items[index]
+}
+```
 
 Alternatively, you can change the property name used as data index by changing the
 `indexAs` property. The `as` property defines the name of the variable to add to the binding
@@ -71,16 +74,33 @@ bound from the model object provided to the template scope):
   <iron-list items="[[data]]" as="item">
     <template>
       <div>
-        Name: <span>[[item.name]]</span>
+        Name: [[item.name]]
       </div>
     </template>
   </iron-list>
 </template>
 ```
 
+### Accessibility
+
+`iron-list` automatically manages the focus state for the items. It also provides
+a `tabIndex` property within the template scope that can be used for keyboard navigation.
+For example, users can press the up and down keys to move to previous and next
+items in the list:
+
+```html
+<iron-list items="[[data]]" as="item">
+  <template>
+    <div tabindex$="[[tabIndex]]">
+      Name: [[item.name]]
+    </div>
+  </template>
+</iron-list>
+```
+
 ### Styling
 
-Use the `--iron-list-items-container` mixin to style the container of items, e.g.
+You can use the `--iron-list-items-container` mixin to style the container of items:
 
 ```css
 iron-list {
@@ -98,7 +118,7 @@ This event is fired by any element that implements `IronResizableBehavior`.
 By default, elements such as `iron-pages`, `paper-tabs` or `paper-dialog` will trigger
 this event automatically. If you hide the list manually (e.g. you use `display: none`)
 you might want to implement `IronResizableBehavior` or fire this event manually right
-after the list became visible again. e.g.
+after the list became visible again. For example:
 
 ```js
 document.querySelector('iron-list').fire('iron-resize');
@@ -111,7 +131,7 @@ visible on the screen. e.g. the page has 500 nodes, but only 20 are visible at t
 This is why we refer to it as a `virtual` list. In this case, a `dom-repeat` will still
 create 500 nodes which could slow down the web app, but `iron-list` will only create 20.
 
-However, having an `iron-list` does not mean that you can load all the data at once. 
+However, having an `iron-list` does not mean that you can load all the data at once.
 Say, you have a million records in the database, you want to split the data into pages
 so you can bring a page at the time. The page could contain 500 items, and iron-list
 will only render 20.